 window.onload = function() {
 	var oForm = document.getElementById('loginForm');
 	var oUser = document.getElementById('username');
 	var oPswd = document.getElementById('password');
 	var oRemember = document.getElementById('remember');
 	//页面初始化时，如果帐号密码cookie存在则填充
 	if(getCookie('username') && getCookie('password')) {
 		oUser.value = getCookie('username');
 		oPswd.value = getCookie('password');
 		oRemember.checked = true;
 	}
 	//复选框勾选状态发生改变时，如果未勾选则清除cookie
 	oRemember.onchange = function() {
 		if(!this.checked) {
 			delCookie('username');
 			delCookie('password');
 		}
 	};
 	//表单提交事件触发时，如果复选框是勾选状态则保存cookie
 	oForm.onsubmit = function() {
 		if(remember.checked) {
 			setCookie('username', oUser.value, 7); //保存帐号到cookie，有效期7天
 			setCookie('password', oPswd.value, 7); //保存密码到cookie，有效期7天
 		}
 	};
 };
 //设置cookie
 function setCookie(name, value, day) {
 	var date = new Date();
 	date.setDate(date.getDate() + day);
 	document.cookie = name + '=' + value + ';expires=' + date;
 };
 //获取cookie
 function getCookie(name) {
 	var reg = RegExp(name + '=([^;]+)');
 	var arr = document.cookie.match(reg);
 	if(arr) {
 		return arr[1];
 	} else {
 		return '';
 	}
 };
 //删除cookie
 function delCookie(name) {
 	setCookie(name, null, -1);
 };